class Viewer
{
public:
    void show();
private:
    class Chess
    {
    public:
        void show();
    private:
        struct Color
        {
            int r, g, b;
        Color(int red, int green, int blue):r(red), g(green), b(blue){
                }
            
        };
        static Color s_colors[2];
    };
};
